This application claims the benefit of Korean No. 2001-78484, filed Dec. 12, 2001, in the Korean Industrial Property office, the disclosure of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to an inkjet printer, and more particularly to an apparatus for and a method of adjusting a position of a printing head mounted in a head carrier of an inkjet printer by adjusting a position of a parallel adjustment shaft contacting a fixing surface of the printing head to be parallel to a carrier shaft of the head carrier.
2. Description of the Related Art
Generally, data or files generated from a computer are changed in a written form by being printed on printing paper through a printer. In changing data or files in the written form, various types of printers are used. For example, an inkjet printer performs a printing operation by heating ink stored in a cartridge to generate bubbles and ejecting the ink by the generated bubbles in a given form on the paper through an ink ejection nozzle.
Usually, an inkjet printer 10, as shown in FIGS. 1 and 2, includes a paper feeder 20 containing printing paper P, a paper transporter 30 transporting the paper P from the paper feeder 20, a printing part 40 printing data on the paper P transported through the paper transporter 30 by moving a head carrier 46 mounted with the printing head 41 therein in right and left directions along a carrier shaft 42, and a paper-discharging part 60 discharging the paper P printed by the printing part 40 to an outside of the inkjet printer 10.
As shown in FIGS. 3 and 4, to correctly eject ink on the printing paper P when the printing head 41 is moved to the right and left directions along the carrier shaft 42 to print data on the paper P, the inkjet printer 10 has a parallel adjustment shaft 44 formed at a lower part of the head carrier 46 to position and fix (mount) the printing head 41 on a lower supporter 45 of the head carrier 46 at a predetermined position, for example the position in which a lower fixing surface 23 of the printing head 41 is maintained to be parallel to the carrier shaft 42.
In an operation, as shown in FIG. 2, the printing paper P contained in the paper feeder 20 is elastically supported by a lockup spring 21 and picked up by a pickup roller 22 and then moved to the paper transporter 30.
At the paper transporter 30, the paper P is transported to the printing part 40 by a rotation of a feed roller 31 and a friction roller 32. Thus, as the paper P is transported from the paper transporter 30 to the printing part 40, a motor 45 driving a head carrier assembly operates to drive a belt 43. Consequently, the printing head 41 having an ink ejection nozzle 41a, which is mounted in the head carrier 46, is moved in the left and right directions along the carrier shaft 42 and ejects ink on the paper P transported by the paper transporter 30 to print pictures or letters thereon.
As the paper P is gradually moved along a base frame 50 after printing by the nozzle 41a of the printing head 41, the printing paper P arrives at the paper-discharging part 60. At the paper-discharging part 60, the paper P is discharged to the outside through paper-discharging rollers 61 and star-shaped wheels 62.
However, in the inkjet printer 10, when due to manufacturing and assembling errors, the lower fixing surface 23 of the printing head 41 is not maintained to be parallel to the parallel adjustment shaft 44 fixed in the head carrier 46, or when the parallel adjustment shaft 44 itself is not maintained to be parallel to the carrier shaft 42, there was no way to adjust a position of the parallel adjustment shaft 44, i.e., an arrangement or orientation of the printing head 41 with respect to carrier shaft 42 or the parallel adjustment shaft 44, since the parallel adjustment shaft 44 positioning the printing head 41 at the predetermined position is fixed to be unmovable at the lower part of the head carrier 46.
Also, even though the printing head 41 is first positioned at a correct position, it can be deviated from the first position by mechanical frictions or loads in the printing operation ever a long period of time, and thereby the first position becomes changed or varying so as not to be parallel to the parallel adjustment shaft 44 or the carrier shaft 42.
If the printing head 41 is not maintained to be parallel to the parallel adjustment shaft 44 or the carrier shaft 42, a xe2x80x9cswitchingxe2x80x9d problem occurs in which ink is unevenly ejected on the paper from the ink injection nozzle 41a of the printing head 41, thereby a printing quality may deteriorate.
Therefore, it is an object of the present invention to provide an improved apparatus for and a method of adjusting a position of a printing head mounted in a head carrier of an inkjet printer, the apparatus controlling an arrangement or orientation of the printing head with respect to the head carrier.
It is another object to provide an improved apparatus for and a method of adjusting a position of a printing head in an inkjet printer by adjusting a position of a parallel adjustment shaft having a fixing surface of the printing head mounted in a head carrier to be parallel to a carrier shaft guiding a movement of the head carrier.
Additional objects and advantageous of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learded by practice of the invention.
These and other objects according to an embodiment of the present invention may be achieved by providing an apparatus adjusting a position of a printing head in an inkjet printer having the printing head ejecting ink to perform a printing operation, and a head carrier mounted with the printing head and moving along a carrier shaft. The apparatus includes a device disposed in the head carrier to adjust an arrangement or orientation of the printing head with respect to the head carrier. The adjusting device includes a positioning member disposed in the head carrier to position and mount the printing head in a predetermined position, and a positioning member adjuster to adjust a position of the positioning member to control the arrangement or orientation of the printing head.
The positioning member includes a parallel adjustment shaft positioning and mounting a fixing surface of the printing head to be parallel to the carrier shaft at a lower part of the head carrier.
The positioning member adjuster includes a first receiving hole formed at the head carrier to receive and support the parallel adjustment shaft moving in a direction perpendicular to an axial direction of the parallel adjustment shaft, an eccentric cam disposed at the head carrier in the vicinity of the first receiving hole to be in contact with the parallel adjustment shaft, an actuation lever formed at one side of the eccentric cam to rotate the eccentric cam, and a pressing part pushing the parallel adjustment shaft to come in contact with the eccentric cam. Preferably, the pressing part includes a first elastic spring disposed in a first mounting groove formed in a wall defining the first receiving hole to push the parallel adjustment shaft toward the eccentric cam.
Also, the positioning member adjuster may be disposed at the head carrier in relation to one end of the parallel adjustment shaft. In this case, a pressing device can be disposed at the head carrier in relation to the other end of the parallel adjustment shaft without an additional positioning member adjuster to push the other end of the parallel adjustment shaft toward the fixing surface of the printing head. The other end of the parallel adjustment shaft is disposed within an adjusting range of the positioning member adjuster without overly moving away from the fixing surface of the printing head. The pressing device may include a second receiving hole formed at the head carrier to allow the other end of the parallel adjustment shaft without the additional positioning member adjuster to be movable in the direction perpendicular to the axial direction of the parallel adjustment shaft, and a second elastic spring disposed in a second mounting groove formed in a second wall defining the second receiving hole to push the other end of the parallel adjustment shaft toward the fixing surface of the printing head.
The positioning member can further include a locking part releasably locking the actuation lever onto one of a plurality of selected positions. The locking part may include a projection formed at an end of the actuation lever, and at least one locking groove formed at a portion of the head carrier corresponding to the projection along a movement path thereof.